Poly oxymethylene-linked

One method of reducing crystallinity in PEO-based systems is to synthesize polymers in which the lengths of the oxyethylene sequences are relatively short, such as through copolymerization. The most notable hnear copolymer of this type is oxymethylene-linked poly(oxyethylene), commonly called amorphous PEO, or aPEO for short. Other notable polymer electrolytes are based upon polysiloxanes and polyphosphazenes. Polymer blends have also been used for these applications, such as PEO and poly (methyl methacrylate), PMMA. The general performance characteristics of the polymer electrolytes are to have ionic conductivities in the range of cm) or (S/cm). 

Andrews76 gave results of the work of Reed and Martin on cis-polyisoprene specimens crystallized from a strained cross linked melt and on solid state polymerized poly-oxymethylene respectively, explaining the results by simple two phase models. He also summarized the studies of Patel and Philips775 on spherulitic polyethylene which showed that the Young s modulus increased as a function of crystallite radius by a factor of 3 up to a radius of about 13 n and then decreased on further increasing spherulite size. 

Highly branched polymers such as polypropylene and polymers with other links, e.g. poly(oxymethylene), are most readily attacked by atomic oxygen. Perfluorinated polymers, rubber vulcanized with sulfur, and highly aromatic polymers are the most resistant. 

Expressions such as —(—O—CH2—) — and (H2N—(CH2)6—NH2 HO2C— (0112)4—C02H)x depict actual structures, not molecular formulae. Although expressions such as (CH20)n and (C6Hi6N2 C6Hio04)a are used by CAS to represent the molecular formulae of poly(oxymethylene) and nylon-6,6 respectively, these expressions are, per se, neither structure-based nor source-based representations of these two polymers. There is a link, however, between the full structural representation and its molecular formula. The subscript n is used consistently for both an SRU and its molecular formula similarly, the subscript x is used consistently for both a homopolymer (copolymer) structure expressed in terms of monomer(s) and its corresponding molecular formula. 

Measurements of the frequency and temperature dependence of the H T, in poly(dimethyl siloxane) revealed relaxations due to methyl rotation and segmental motions and also an oxygen impurity effect The experimental data could not be fitted using thermally activated Arrhenius behaviour, as was also true of backbone motions in poly(vinyl chloride). " Multiple side-group motions have also been observed in poly (diethyl siloxane) and poly(L-histidine). Backbone motions have been observed in poiy(diethyl siloxane), poly(oxymethylene), poly(ethylene terephthalate), poly(p-phenylene sulphide), aromatic polyamides, and PTFE. A close similarity between the effects of entanglements and radiation cross-linking on the of cis-polyisoprene has been found. ... 

Ozer et al. (1998) reported a sol-gel EC-device of the configuration glass/FTO/ WOs/a-PEO/NiO cHy/ FTO/ glass with a lithiated oxymethylene-linked poly(ethylene oxide) (a-PEO) ion conductor. The devices had a fast optical response (50 s) and a transmittance change from 80% to 50% at 550 nm but a short cycling lifetime. 

Atomic oxygen reacts rapidly with several polymers [655, 803, 905-907, 1294, 1362, 1387, 1776, 1777, 1839, 1958]. Figure 7.1 shows the effect of atomic oxygen on the weight loss of different polymers. Highly branched polymers such as polypropylene and polymers with ether links, e.g. poly-(oxymethylene), are most readily attacked by atomic oxygen. Perffuorinated polymers, rubber vulcanized with sulphur and highly aromatic polymers are... 

With these words, Hermann Staudinger referred in his Noble lecture to the degradability of poly-oxymethylene (POM) in contrast to its a,co-dimethyl ether derivative [1], linking the structure-property relation of an entirely synthetic polyacetal to biological processes. Sixty years later, we realize that his statement is not only true for the natural macromolecules he had in mind, such as DNA or proteins, but also for synthetic polymers designed for in vivo applications. 

Poly(ethylene glycol) has been chain extended to a high molecular weight amorphous rubbery linear polymer using an oxymethylene link." This polymer, when doped with lithium perchlorate, shows similar conductivity to MEEP and because of its chemical similarity to PEO provides an interesting comparison to show the effect of crystallinity." ... 

Solid polymer electrolyte (SPE) based on oxymethylene-linked poly (oxyethylene) (OMPEO) with a mixture ofPEG400 and 600... 

Gel polymer electrolyte (GPE) based on poly (methyl methacrylate)/ oxymethylene-linked poly (oxyethylene) (PMMA/OMPEO) blend composite... 

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